Telentospores. 3 7 



vested with a thick membrane (Plate III. Figs. 18, 19). 

 Their subsequent development is similar to that which 

 occurs in the uredospores. The investing membrane, 

 however, undergoes considerable thickening, and becomes 

 darker in colour. At the apex of the spore this thicken- 

 ing is most marked, but it does not always follow that 

 here the depth of its colour is most noticeable, although 

 it generally is so. This is, to a certain extent at any 

 rate, owing to the fact that the apex of the spore is per- 

 forated by a small tubular canal, which is, however, by 

 no means easy to observe in the perfect spore, but whose 

 presence is obvious enough in those spores which have 

 already germinated, or are in the act of germinating. 

 The interior of this membrane is lined by a very thin 

 endospore. This can be brought into view by the action 

 of undiluted sulphuric (H2SO.1) or nitric acid (HNO3). 

 These reagents exert no influence on the investing mem- 

 brane, but cause the endospore to shrink away from it. 

 The endospore encloses a finely granulated protoplasmic 

 mass, near the middle of which is usually a vacuole. The 

 teleutospore remains for a. longer or shorter period attached 

 to the spore-bed by the lower part of its spore-forming 

 hypha, which contains a hyaline or watery material, and 

 constitutes a stem (pedicel, peduncle) to the teleutospore, 



Teleutospores may be simple (Uromyces, Melampsora) 

 or compound (Puccinia, Triphragmium, Chrysomyxa). 



The teleutospores of Uromyces are developed in the 

 manner above described. The germinal canal is always 

 at the apex of the spore. The membrane is generally 

 smooth, but in some species, as Ur. alcJieviillcB, it is 

 studded with prominent wart-like tubercles. Similar 

 tubercles are observed on some of the species affecting 

 the Leguminosae, but instead of remaining as discrete 

 tubercles they become in part or wholly confluent, so as 



